Since about the beginning of the twentieth century, utility companies have employed persons as meter readers to walk routes, visually read utility meters, and record the current readings. The raw data is transcribed by clerical workers in the utility customer accounts department, more currently by key entry into a data terminal of a customer billing computer, where the current reading for an account is compared with the previous reading to determine utility usage for the period. Any errors in reading the meter, recording the data, or transcribing the data results in costly inefficiencies in the billing procedure by overcharging or undercharging the customer which must then be corrected, often by a special service call to the customer's home or business. Utility companies have sought to increase the efficiency of meter reading and to reduce errors throughout the billing procedure.
In general, these problems are reduced by reducing the involvement of humans in the data communication chain from the meter to the billing computer. One of the problems associated with changing the billing procedures of a utility company is the large scale of the effort. A utility company in a large metropolitan area may have hundreds of thousands, even millions, of service connections and, likewise, meters. Thus, modifying or replacing the meters of a company can be very expensive, as well as complex and confusing during the changeover period.
One class of approaches to solving these problems is remote meter reading. In one type of remote meter reading, each meter is provided with a small sensor or computer combined with a radio transponder which records utility usage and sends a code string identifying itself and conveying the usage data when interrogated by a compatible meter reading transponder unit on a utility truck which drives in the vicinity. A computer in the truck stores the data received from each meter interrogated for subsequent uploading to the utility billing computer.
One problem with radio linked metering is the expense of adding a meter sensor and radio transceiver to a great number of meters. Additionally, utility meters are often located outdoors, so that such a meter sensor and transceiver would have to be capable of operating precisely in extremes of temperature, moisture, and sunlight as well as protected from vandalism and animals. While such protection is within the capabilities of the state of the art of electronic devices, it would add further to the cost of implementing such a billing procedure.
Another remote metering approach which has been considered is interfacing a meter sensor to the utility billing computer by way of the customer's telephone line or television cable. Interrogation of the customer's meter generally occurs when the transmission line is not in use for its primary purpose to avoid possible interference, that is, when no call is in progress on a telephone line or when a television connected to the television cable is not in use.
Meter reading over existing communication lines requires the involvement of the telephone company or cable system for data gathering and transfer to the utility company. This adds a layer of complexity to the billing and the resolution of billing disputes. While most households have telephone connections, some do not have cable connections. If service to these facilities is interrupted by nonpayment of bills, weather, or accidental cutting of the service lines, billing is also interrupted. Thus, such an approach might require conventional meters as backup for such contingencies. Additionally, some customers might object to such a billing method on privacy grounds because of fears that their private activities are being surreptitiously monitored.
In addition to the practical problems of remote meter reading mentioned above, there are advantages to having utility personnel periodically visit each installation. This allows for at least a cursory inspection of the meter to note its condition, whether vandalism has occurred, or if a safety situation exists which warrants immediate repair, such as evidence of a gas leak around a gas meter.
Another class of improvements in utility billing procedures is based on increasing the efficiency and precision of readings taken by meter readers. These methods include portable data entry devices into which the meter reader enters the meter reading and other pertinent information by a keypad on the device for eventual uploading into the billing computer. Use of this type of device requires no modification of existing meters and allows an inspection of the premises of each installation, but has the possibility of error from miskeying of data. In another method, a sensor is interfaced to the meter and is interrogated through an infrared communication link by a portable data collector. This method is similar to and suffers from some of the same problems as remote radio linked meter reading but has the advantage of an on-site reading by a meter reader.
What is needed to improve utility meter reading is an approach which requires minimal modification to existing types of utility meters, which is rugged and inexpensive, and which incorporates the periodic personal presence of a meter reader at each installation but does not require the meter reader to transcribe or key in the usage date.